Oh man, you sure know how to drive a stake in my heart! What have I done! Some curses should just not be uttered. I'm not sure where it is on my backups.
But it was done just like you'd do it in C++. The same thing, just with D syntax.
We're making a numerical computing library that expression templates are used for compile-time evaluation of expressions. It's a very niche hpc library, so it might be one of the few places it's appropriate.